Method for producing wells



Sept. 12, 1939. A. ARMENTROUT Er Al.

METHob FOR PRoDUcING wELLs 3 Sheet-Sheet 1 Filed Feb. 16. 1938 Illll Sept l2, 1939. A. L. ARMENTRQUT Er AL 2,173,034

METHOD FOR PRODUCING WELLS 3 Sheets-Sheet 2 Filed Feb. 16, 1938 llllll /9 aff/gy Sept. l2, 1939.

A. L. ARMENTROUT El' AL METHOD FOR PRODUCING WELLS 5 Sheets-Sheet 3 RAL a Filed Feb. 16,

Patented Sept. 12, 1.9739

UNITED STATES PATENT. -oFFlcE arza'osi METHOD FOR PRODUCING WELLS Application February 1s, 193s, semi No. 190,740

19 Claims.

This invention' has to do with the production of fluids from wells and has particular reference to methods for recovering or producing fluids from deep wells, such las oil wellsvand gas wells. A

5 general object of this invention is to provide a simple, efficient and commercially practical method for producing fluids from wells.v

Another and important object of this invention is to provide a method by means of which two or l more spaced or separate strata may be simultaneously produced through separate tubes or strings. Another object of this invention is to provide a method of the character mentioned in which the fluids obtained from the several or spaced strata are not commingled.

Another object of this invention is to provide a Amethod of the character mentioned in which the fluids from the productive strata cannot become contaminated with water or other unwanted fluid. Another object of this invention is to provide a method of the character mentioned in which the fluid obtained from a productive zone is produced through and delivered to the ground surface through a single casing having a perforate portion at the productive zone, and a lower productive zone is produced through a liner and the fluid received therefrom is delivered to the ground surface through a tube extending down through said casing.

Another object of this invention is to provide a method of the character mentioned in which the flow from the producing zone into the casing may be induced and, if necessary, maintained by a gas lift action in which the gas is circulated down around the casing.

Another object of this invention is to provide a method of the character mentioned in which the lower end of the casing and the upper end of the liner are simultaneously cemented to secure the same in place and to provide a seal about the same.

The various objects and features of our invention will be fully understood from the following detailed description of a typical preferred manner of carrying out the method of our invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is a vertical sectional view of the lower portion of a well illustrating a casing in position 50 therein. Fig. 2 is a view similar to Fig. 1 showing the inner or combination casing cemented above a productive zone in accordance with the invention. Fig. 3 is a view similar toI Fig. 2 illustrating the manner in which fluid may be circulated through the outer casing to remove excess cement (Cl. 16S-21) from the same, Fig. 4 is a view similar. to -Fig..2 illustrating the condition of the combination ca'sg ing following the drilling out of the float collar. Fig. 5 is a reduced vertical sectional view of the lower portion of the well illustrating a liner 5 cemented to the lower end of the combination" I casing to extend downwardly therefrom, and Fig. 6 is a view similar to. Fig. 5 showing'a string e of tubing connected with the liner to receive the well fluid therefrom. Fig. 7 is a diagrammatic Vfragmentary vertical section of a portion of a well showing a liner hung and cemented therein to pass through spaced productive zones. Fig. 8 is a. view similar to Fig. 7 showing a flow string arranged in place to receive fluid from one portion of the liner and showing a second liner cemented in the well and Fig. 9 is a view similar to Fig. 8 illustrating a second or inner flow or produicng e string connected with said second liner to receive .uid therefrom. y

The method o f the present invention-V may be varied somewhat to adapt it for employment under different operating conditions. Infthe drawings we have illustrated two manners ,Y of carrying out the invention in obtaining or pro- 25 ducing fluids from a typical oil well or gas well. It is to be understood that the invention is not to be construed as limited or restricted to the specific details or applications of the invention illustrated in the drawings.

'I'he portion of the well W illustrated in the drawings penetrates a non-productive stratum A, a water sand or stratum B bearing unwanted fluid, a non-productive stratum C underlying the stratum B, a productive stratum D underlying the stratum C, a non-productive stratum E underlying the stratum D, and a lower productive stratum F below the stratum E.

'I'he method `of the present invention, ,as illustrated in Figs. 1 to 6 inclusive, may be said to comprise, generally, the setting or cementing of a casing I0 in a well W, the deepening of the well W to penetrate the productive strata D and F, the landing of a combination casing II in the well having a perforate portion I2 in the stratum D, cementing the combination casing II in the well W' above the stratum D, arranging a liner I3 in the well Wto project downwardly from the combination casing I I and to extend through the stratum F, cementing the combination casing II and the liner I3 in the well W between the productive strata D and F, connecting a tubing I 4 (see Fig. 6) with the liner I3 to receive the produced fluid therefrom, and then, if necessary, circulating gas through the casings I0 and II to induce produc- 55 tion from the stratum D. A string of casing such as casing II, including both perforated and imperforated sections, is commonly referred to as a combination casing.

The casing I 8 may be a typical water string or casing landed at the derrick to extend downwardly in the well W to the stratum A. The lower portion of the casing I0 is imbedded in cement I5l in the usual manner. 'I'he casing I0 and the cement I5'L excludes water and other operated through the casing I8 to deepen the well W. The well W may be of uniform diameter from the casing I8 to a point within or below the stratum F or it may be drilled in stages as will be subsequently described to have a reduced lower portion extending from the stratum E through the stratum F. When the well W is deepened in stages, as just mentioned, an upwardly facing shoulder I5 is formed on the wall of the well W. In the drawings we have shown the shoulder I5 in the portion of the well penetrating the non-productive stratum E. It is to be understood that the locations and vertical extents of the several strata A, B, C, D, E and F are logged or recorded as the well is drilled or deepened.

The combination casing II is provided to extend from the upper end of the well to a point within or below the productive stratum D. In accordance with the invention the combination casing II is constructed and arranged to serve both as a lining or casing for the well and as a screen or liner for admitting `fluids fromthe productive stratum D. The combination casing I I may be assembled and run into the well W in the usual manner. The combination casing II is proportioned to extend through the casing I8 with .substantial clearance leaving an annular space I6 in the casing I8. When the combination casing II is landed at the derrick it extends downwardly beyond the lower end of the set casing I0 to enter or pass through the stratum D. In accordance with the invention the casing I8 is provided with ports or openings I-'I in its side wall adjacent or above the lower end of the set casing I0. In the preferred manner of carrying out the invention the openings I1 are spaced some distance above the lower 'end of the casing I8. 'Ihe combination casing II may be made up of a number of lengths or sections connected by couplings or collars in the usual manner.

A cement basket I8 is provided on the combination casing II at a point some distance below the openings I1. The spacing of the basket' I8 from the openings I1 depends upon the positions and extents of the strata B, C and D. Where a stratum B bearing unwanted iluid occurs between the lower end of Athe casing I8 and the productive stratum D the basket I8 is arranged to be between the strata B and D and within the stratum C when the combination casing II is landed.

The combination casing II is further provided witha float shoe or iloat collar 20. The collar may be connected between two lengths or sections of the-combination casing II. As illustrated in the drawings the collar 20 includes a nipple or collar 2| of steel, or the like, threadedly connected with the adjacent ends of the two casing sections and a body 22 of drillable material cast or otherwise secured in the collar 2l. The body 22 is formed of lead, aluminum, Bakelite, glass, cast iron, cement or other drillable material. A central insert 28 of Bakelite or other drillable material is provided in the upper portion of the body 22 and has a central vertical socket or opening 24. A downwardly facing valve seat 25 is provided in the opening 24 and a ball- 26 is arranged to seal upwardly against the seat 25. Transverse openings 21 extend through the collar 2|, the body 22 and the insert 23 to communicate with the opening 24 below its seat 25.

The perforate portion I2 is provided on the combination casing II to receive the well fluid from the productive stratum D. 'Ihe perforate portion I2 is located in or on the combination casing II to enter or extend through the portion of the well W penetrating the stratum D when the casing is landed. The length of the perforate portion I2 is determined by the vertical extent of the productive stratum D. In the typical installation illustratedthe perforate portion I2 is the lowermost section of the combination casing Il and extends downwardly from the stratum C to the stratum E to pass completely through the productive stratum D. It will be understood that the perforate portion I2 of the combination casing II may be made up of a plurality of connected lengths or sections, if necessary. A suitable shoe 28 is provided on the lower end of the perforate portion I2. The combination casing II is received in the open portion of the well W below the casing I8 with suitable clearance leaving an annular space 29 in the well.

Where the well W is drilled to the depth illustrated in the drawings prior to the introduction of the combination casing II, the combination casing II is preferably made up so that the shoe 28 is a short distance above the shoulder I5 when the casing is landed at the well derrlck. If desired, the well W may be drilled to the depth of the shoulder I5 and the combination casing Il may be landed and cemented before the well is deepened to reach the productive strata F. The invention contemplates either of the above procedures.

rI'he next phase or step of the method is the cementing of the combination casing II in the well W at a point above the productive stratum D. The combination casing II is cemented in the well above the stratum D to .close off the space 29, to seal off the lower end of the set casing I0, and to seal oiI the stratum B, and any other strata, bearing unwanted fluid, that may occur between the lower end of the set casing I0 and the productive stratum D. In carrying out this operation a cementing string 3,0 is

run down through the combination casing II and is connected with the above described float collar 20 to supply cement thereto. The string 30 is tubular and is made up of a. number of sections threadedly connected by couplings (not shown). The cement string 38 is received in the combination casing` II with substantial clearance and its lower portion is adapted to be threaded in the opening 24 of the insert 23 (see Fig. 2). When the string 30 has been threaded in the opening 24 cement slurry which will herein be termed cement 3|, is pumped down through the string 30 to pass through the openings 24 and 21 into the space 29. The capacity or volume of that portion of the space 29 between the basket I I and the openings I1 is estimated or calculated and sumcient cement 3l is pumped down through' the string 30 to fill the said portion of thespace 23. 'The basket I3 limits the down flow of the cement 3| and the cement lllls the space 23 from the basket upwardly to or beyond the lower end ol' the casing I3 to completely surround the adjacent part of the combination casing II. In practice the cement 3l extends upwardly into the lower portion of the casing I3 adjacent to or beyond the openings I1. It is to be noted that the cement 3Iseals oil the lower end of the casing I and seals of! and protects the stratum D from all water sands, and the like, above it.

As illustrated in Fig. 2 of the drawings, the cement 3l may extend up in the casing II) to above the openings I1 to seal oil the same. The invention provides for the removal of this excess cement 3l to leave the openings I1 free or clear. As illustrated in Fig. 3 of the drawings the cement string 33 is unthreaded from the opening 24 and raised slightly so that its lower end is open to the interior of the casing Il above the body 22. Water or other cleaning fluid is then pumped down through the casing I0 from the upper end of the well to discharge inwardly through the openings I1. The cleaning fluid from the openings I1 flows downwardly through the combination casing Il to the lower end of the cement string 30 and returns to the ground surface through the string. If believed necessary the upper end of the combination casing II may be closed to insure the return flow of the circulation fluid or cleaning fluid up through the string .30. The cleaning iluid following the course indicated by the arrows in Fig. 3 of the drawings removes excess cement 3i to a plane at or below the openings I1 so that the same are left open to the interior of the combination casing Il and removes any cement that may have collected in the casing II. When the openings I1 have been cleared as Just described, the cement string 30 is removed from the combination casing Il.

When the cement 3| has been allowed to set and harden the combination casing II is cleared to facilitate the introduction of the liner I3 into the well W. A suitable .drilling tool or the like is run into the combination casing II and is operated to drill up or break out the frangible or drlllable body 22. Fig. 4 of the drawings illustrates the condition of the combination casing II after the body 22 of the collar 20 has been removed-or drilled out. In the event that the well W has not been previously drilled beyond the shoulder I a drilling tool may be operated in the well at this timel to deepen it to the stratum F.

The liner I3 is then run into the well W. 'I'he liner I3 is passed down through the combination casing II to assume a position where it extends from the lower end of the combination casing Il into or through the portion of the well penetrating the productive stratum F. The liner I3 is an elongate tubular assembly having a perforate lower portion to extend through the stratum F and receivethe fluid therefrom. 'A shoe 32 is provided on the lower end of the liner I3 and has blades 33 adapted to engage the bottom wall of the well W. The shoe 32 may serve to support the liner I3 and its blades 33 may operate to prevent turning of the liner I3. The liner I3 is preferably constructed or proportioned to be received in the open portion of the well W with clearance to leave an annular space 34 and to extend upwardly into the lower end of the combination casing li. The upper portion 33 of the liner I3 which extends through the stratum E and other non-producing strata be- 5 tween the strata D and F is imperforate.

In accordance with the invention a float collar is connected in the liner I3 to occupy' a position between the productive strata D and F. This float collar may be similar to the float collar described above. The iloat collar of the liner I3 includes a nipple or collar 36 interposed between and connecting sections of the liner por' tion 35 and a frangible or drlllable body 31 in the collar 36. Lateral ports 33 extend through 15 the collar 33 and the body 31 to communicate` with a central vertical socket 33 in the body 31. A valve 40 is provided in the socket 39 .to seat upwardly and close the socket against` an upilow o! -fluid. A cement basket 4I is provided on the liner I3 at a point below the collar 36. The liner I3 may be lowered or run into the well W on the lower end of a run-in string 42. The run-in string 42 is detachably connected with the upper end of the liner I3. In the simple case illustrated in the drawings the lower end of the run-in string 42 carries an adapter 43, threaded in'a collar 46 on the upper end of the liner I3.

When the liner I3 has been arranged in the selected position in the well W the upper portion of the liner I3 and the lower end part of the combination casing II are cemented in the well W. The volume or capacity of the annular space 34 from the basket 4l to the shoulder I5 isdetermined or estimated and a sulcient quantity of cement slurry or plastic cement 44v.is pumped down through the run-in string 42 to discharge through the openings 38 and occupy the space 34 from the basket 4I to the shoulder I3 and-to extend upwardly into the well above ythe shoulder I5. In practice sulcient cement 44 is delivered to the well W to extend upwardly into the space 23 and to enter the lower end part of the combination casing II. A tubular extension may be connected with the adapter 43 'to extend downwardly in the liner I3 to or adjacent the socket 33 so that the cement is delivered directly to the socket.

It is to be observed that the cement 44 closes or seals ol! the annular space between the telescopically related combination casing II and liner I3, seals about the`lower end part of the combination casing II and seals about the upper portion of the liner i3 above the stratum 5 F. Accordingly, the cement 44 effectively seals oil the well W between the spaced production strata D and F. After sufcient cement 44 has been delivered to the well W the run-in string 42 is disconnected from the liner I3 and withdrawn from the well. When the cement 44 has been permitted to set and harden a drilling tool or the like is run down through the combination casing II and is-operated to drill up or vbreak out the drlllable body 31.A The drilling tool is then withdrawn from the well.

Following the removal of the drlllable body 31 from the liner I3 a flow string I4 is run down through the combination casing II to have its lower end communicate with the liner I3. The 70 flow string I4 is provided to receive the uid of the stratum F from the liner I3 and to. conduct thesame to the ground surface. The upper end of the liner portio 35forms an upwardly facing shoulder 41 within the collar-43. The ow 76 string I4 carries a packer 48 which is adapted to enter the collar 46. The packer 48 is provided with a packing assembly which is actuated through engagement with the shoulder 41 to seal with the interior of the collar 46. The packing assembly serves to prevent the passage of fluid from the liner I3 to the combination casing II and to prevent the downward flow of fluid from the combination casing II to the liner.

Following the connection or association of the flow string I4 with the liner I3 the well W may be allowed or caused to produce from the production strata D and F. Fluid from the stratum F is received in the perforate liner I3 and is allowed to ow up through the liner and the ow string I4. If necessary the 'fluid may be pumped up through the flow string I4. The fluid from the productive stratum D enters the perforate portion I2 of the combination casing II and is allowed or caused to ow up through the combination casing II to the ground surface. If the stratum D fails to iow as desired, air or gas under pressure may be forced down throughl the space I6 to discharge into the combination casing II through the openings I1 and then ow upwardly through the combination casing II. The upward iiow of this air or gas in the-combination casing II may inducev the flow of fluid from the stratum D, the upwardly moving gas having an air lift or gas lift action.

The method of the present invention as described above provides for the production of uid from spaced strata in a well through separate or individual tubular strings. The fluid from the stratum -F iows up through the ow string I4 while the fluid from the stratum D passes up through the combination casing II. 'I'hus the fluids from the spacedproductive strata are prevented from commingling. The cement 44 seals oi about the telescoplng parts of the combination casing II and the liner I3 and sealsoff the well W between the productive strata D and F to keep the production from the two strata separate. It is to be particularly noted that the combination casing II serves both as a. casing or'lining for the well and as a liner for admitting the fluid produced from the stratum D. The combination casing II also serves as a production string for conducting the produced fluid to the ground surface. The combination casiing II provided with the perforate portion I2 and cemented in the well W above and below the stratum D, as described above, takes the place of a liner and makes it unnecessary to provide a liner for receiving the uid from the stratum D. The liner I3 with its associated production string I4 may be considered as a tubular string extending through the combination casing II to handle the fluid from the stratum F.

Figs. '7, 8 and 9 of the drawings illustrate the method of the invention employed to produce from three spaced productive zones L, M and N in a well X.

The method of the invention as illustrated in Figs. 7, 8 and 9 of the drawings may be said to comprise, generally, the drilling of the well X to penetrate the several productive zones L, M and N; the landing and setting of a casing in the well X; setting a liner 6I in the well X to have perforate portions 6I*al and IIb at the zones L, and M, respectively; the cementing of the liner 6I in the well X at a point between the zones L and M; arranging a flow string 63 l'us fluid from the zone L to be produced through the liner 6I andrthe casing 60; arranging a liner 64 in the zone N, cementing the liners 6I and 64 in the well X between the productive zones M and N and then arranging a flow string 65 through the string 63 and the liner 6I to receive the fluid from the liner 64.

The Well X may be drilled through the spaced productive zones L,'M and N at one operation, or may be drilled in stages. Following the drilling of the well X the casing 60 is landed at the derrick to have its lower end above the uppermost productive zone L. The lower portion of the casing 60 is cemented in the well in the usual manner. The casing 60 forms a water string for shutting on unwanted fluid from the strata above the productive zone L.

Following the setting of the casing 60 the liner 6I is made up and run down through the casingA 60 into the open lower portion of the well X. The liner 6I is constructed to have its perforate portion 6Ia extend through the part of the Well penetrating the productive zone L' and to have its perforate portion SIb extend through the part of the well penetrating the productive i zone M. The intermediate portion 6Ic of the liner 6I connecting its portions 6Ia and IIb is imperforate. The liner 6I may be arranged or suspended in the well X in any selected man- As diagrammatically illustrated in the drawings the liner 6I may be suspended from the set casing 6U by a suitable liner hanger 66. When the liner 6I is suspended in this manner the hanger 66 embodies packing means for sealing with the set casing 60 to' provide a seal between the liner and the casing. The upper portion of the liner 6I or its portion 6I or both, may be drlllable to permit sidetracking ofthe well.

After the liner 6I has been arranged in the well X as described above its imperforate portion 6Ic is cemented in the well between the productive zones L and M. Thus a barrier B'I of cement is provided in the well X between the zones L and M and surrounding the liner portion BIG. In practice the liner 6I may be cemented in the well X between the zones L and M in the same manner as the combination casing II is cemented in the well W at the strata. B and C, as described in the foregoing form of the invention. The cement barrier 61 effectively seals oi the well X between the spaced productive zones L and M. 'I'he liner 6I is constructed to extend downwardly through the zone M and to have an imperforate portion Bld'in the well between the zones M and N. I

The flow string 63 is then run down through the set casing 60 and the liner 6I to have its lower end in the liner portion BIC. The flow string 63 extends down through the casing 6D with clearance, leaving an annular space 10. In practice the flow string 63 maybe provided with means for packing or sealing with the liner 6| between the productive zones L and M. A suitable lead seal packer 'II may be provided on the lower end of the flow string 63 to seal with the imperforate liner portion 6Ic. The packer 'II may be actuated by manipulation of the flow string 63 when the string has been run into the well. The portion of the ow string 63 extending through the upper part of the liner 6I `and its drillableportion 6I is preferably drlllable to facilitate sidetracking of the well. 'I'he ow string 63 preferably has a releasable connection 'I2 with its packer I I.

Following the arrangement of the ow string rvsA 63 in the well, as described above, the liner 64 is run down through the fiovv string 63 to a position in the productive zone N. `It is to be understood that the liner 64 may be arranged in the well X prlorto the introduction of the flow string 63 to the well if this course is desired. The liner 64 may be suspended or held in the well X in any desired manner. In the simple case illustrated the lower end of the liner-64 rests on the bottom of the well X. The liner 64 is constructed ,to extend upwardly through the zone N and to enter the lower portion of the liner 6I. The portion of the liner 64 passing through the stratum or. zone N is perforate to receive the fluid therefrom. The portion of the liner 64 entering the liner 6I is preferably imperforate.

When the liner 64 has been arranged in place the telescoping parts of the two liners 6I and 64 are cemented in the well X to close off the well between .the zones M and N.4 This cementing of the telesgoping liners 6I and 64 in thenwell X may be performed in the same manner as the cementing of the telescoping parts of the combination casing II and the'liner I3 in the well W as described above. The cement barrier 14 in the well X between the zones M and N seals off the space between the telescoping parts of the liners 6I and 64 and seals off the well X around the lower portionof the liner 6I and the upper portion of the liner 64. 'I'hus the barrier 14 .effectively separates the two zones M and N.

Following the provision ofthe cement barrier 14 as described above, the second or inner flow string 65 is run down through the string 63 and is connected with or associated with the liner 64 to receive uid therefrom. The secondor inner fiowstring 65 extends down through the string 63 with substantial clearance leaving an annular space 15 for passing iuid. The lower portion of the second flow string 65 may be connected with the upper portion of the linerv 64 in the same manner as the string I4 is connected with the liner I3 in the previously described form of the invention. When the second fiow string 65 has been connected with the liner 64 the spaced strata or zones L, M and N are allowed to produce or are caused t produce.

'It will be observed that the method of theinvention illustrated in Figs. "I, 8 and 9 provides for the production of fluid from three separate or spaced productive zones L, M and N in a well X. The fluid from the zone L produces upwardly through the liner 6I and through the set casing 60. The fluid from the stratum or zone M enters the portion 6Ib of the liner 6I and passes upwardly through the string 63 to the upper end of the well and the fluid from the zone N passes through the liner 64 and enters the string 65 to pass to the upper end of the well. In this manner fluid from the three spaced zones-L, M and N are separately produced and do not commingle.

Having-described vonly typical preferred manners of carryingout the method of our invention, we do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to ourselves any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims:

Having described our invention, we claim:

1. The method of producing a well having spaced productive zones which comprises providing a tubular structure extending downwardly from the surface of the well. and having a perforate portion positioned at one of said zones, sealing off about said structure above said zone, ar-

ranging a perforate liner in the well to project from said structure into another of said zones,-

A the cementing string from the well,"and arranging a flow string through the casing to' receive the fiuid from said liner and to conduct it to the upper end of the well.

2. The method of producing fiuid from spaced productive zones penetrated by a well which comprises individually producing from the zones by first arranging a tubular string in the well to have a perforate portion receive the fiuid from one of said zones and to conduct said uid to the ground surface, then arranging a second tubular string inthe first named string to extend beyond the lower end thereof and having a perforate portion to receive the fluid from a second productive .zone and to conduct the iiuid tothe ground surface, and introducing a body of cement into the well at a point between said zones to` provide a barrier around the said first named string and a barrier between the strings.

3. The method of producing a well that penetrates a productive zone which comprises arranging a casing in the well to have its lower end above said zone, arranging a tubular string through the casing to receive the fiuid from said zone and to have communication with the interior of the casing, cementing said string in the Well between said zone and the point of its communication with the casing, and circulating a fluid down through the casing to pass into thestring and upwardly therein to induce the iiow of fluid from said zone up through said string.

4. The method of producing a well that penetrates spaced productive zones which comprises arranging a casing in the well to have its lower end above the uppermost productive zone, ar-

ranging a first tubular string through the casing to project downwardly therefrom and having a portion in communication with one of said zones to receive fluid therefrom, running a liner down through the said first string on a second tubular string to receive fluid from another of said zones,

passing cement down through said second tubular string to cement the lower portion of said first tubular string and the liner in the well, removing said second tubular string from the well, and then associating a flow string with the liner to receive the fluid therefrom and conduct it from the well.

5. The method of producing fluid from spaced productive zones penerated by a well which comprises individually producing from the zones by first arranging a first tubular string in the well to have a perforate portion receive the fiuid from one zone and to conduct the fluid to the upper end of the well, cementing said first tubular string in the-well above its respective productive'zone, running a liner into the well on a second tubular string to a position in another productive zone,

passing cement down through said second tubular' string to cement the liner in the well, removing said second tubular string from the well, and then associating a flow string with the liner to conduct uid therefrom to the upper end of the well.

6. The method of producing uid from spaced productive zones penetrated by a well which comprises individually producing from the zones by rst arranging a first tubular string in the well to have a perforate portion receive the fluid from one zone and to conduct 4the uid to the upper end of the well, cementing said iirst string in the well above its respective productive zone, running a liner into the well on a second tubular string to a position in another productive zone, passing cement down through said second tubular string to form a cement barrier in the well around the liner and the lower end of said first tubular string and between the first and second mentioned zones, removing said second tubular string from the well, and then associating a flow string with the liner to conduct fiuid therefrom to the upper end of the well.

7. The method of producing a well having spaced productive zones which comprises setting a casing in the well above the uppermost productive zone, arranging a perforate liner in the well to pass through spaced productive zones, providing a barrier around said liner and between the last mentioned zones, and then arranging a ow string through the casing with clearance to receive the uid from the portion of the liner below said barrier and to allow the iiuid from the zone above said barrier to pass up through the casing.

8. The method of producing a well havin spaced productive zones which comprises setting a casing in the well above the uppermost productive zone, arranging a perforate liner in the well to pass through spaced productive zones, providing a barrier around said liner and between the last mentioned zones, arranging a ow string through the casing with clearance, and packing off between the iiow string and the liner whereby fluid received by said liner below said barrier is produced. through the iiow string and the fluid received by said liner above the said barrier is produced through the casing.

9. The method of producing a well having spaced productive zones which comprises setting a casing in the well above the uppermost productive zone, arranging a perforate liner in the well to pass through spaced productive zones, providing a barrier around said liner and between the last mentioned zones, arranging a flow strin'g through the casing with clearance, packing off between the flow string and the liner whereby iiuid received by said liner below said barrier is produced through the flow string and the fluid received by said liner above the said barrier is produced through the casing, arranging a liner in the well to receive fluid from a productive zone below the lower end of the rst mentioned liner, sealing off between said liners, and then connecting a flow string with the'last mentioned liner to receive the uid therefrom and to'pass upwardly through the last mentioned flow string with clearance.

10. The method of producing' a well having spaced productive zones which comprises setting a casing in the well above the uppermost productive zone, arranging a perforate liner in the well to pass through spaced productive zones, providing a barrier around said liner and between the last mentioned zones, arranging a fiow string through the easing with clearance, packing off between the fioW string and the liner whereby uid receivedby said liner below said barrier is produced through the flow string and the fluid received by said liner above the said barrier is produced through the casing, arranging a second liner in the well to receive uid from a zone below the first mentioned liner and to extend upwardly into said first mentioned liner, cementing the telescoping portions of the liners in the well, running a second flow string through the first ow string with clearance, and then connecting the second now string with the second liner to receive the fiuid therefrom.

11. 'I'he method of producing a well having upper and lower producing strata which includes positioning tubular means in the well, said means having perforations oppositeeach stratum, effecting a barrier on the exterior of the tubular means so as to prevent commingling of fluids from the strata on the exterior of the tubular means, positioning a now string in the perforated means to receive fluid through the perforated means from the lower stratum and to conduct it to the surface, and eiecting a barrier between the iiow string and the tubular means to prevent commingling of fluids from the strata within the tubular means.

12. The method of producing a well having upper and lower producing strata which includes positioning a tubular means in the well, said means having perforations opposite each stratum, cementing on the exterior of the tubular means to effect a barrier on the exterior of the tubular means to prevent commingling of fluids from the strata on the exterior of the tubular means, positioning va. flow string in the tubular means to receive fluid therethrough from the lower stratum land to conduct it to the surface, and effecting a barrier between the flow string and the tubular means to prevent commingling of fluids from the strata within the tubular means.

13. The method of setting a liner in a well which includes setting a liner so that its upperend extends into the bottom of another tubular member in the well, and simultaneously forcing cement between the top of the liner and the tubular member and between the vtubular member and the well walls.

14. 'I'he method of setting a liner in a well which includes setting a liner so that its upper end extends into the bottom of another tubular member in the well, forcing cement in one operation between the upper portion of the liner and the well walls, between the tubular member and the well walls and into the space between the liner and the tubular member. v

15. 'I'he method of producing wells which includes setting an upper tubular member in a well having perforations opposite an upper productive stratum, setting a lower tubular member in a well so as to extend fromrwithin the bottom of the upper tubular member into a lower productive stratum, said lower member having perforations opposite the lower stratum, effecting a seal between the bottom of the upper member and the well walls and between the bottom of the upper member and the top of the lower member, and detachably connecting a ow string to the lower member so as to convey fluids received thereby to the surface without commingling with uids from the upper stratum.

16. The method of producing wells which includes positioning a tubular member in a well so as to extend through two productive strata, said tubular member having perforations opposite said strata, effecting a barrier between the tubular member and the well walls so that iiuids from the two strata cannot commingle on the outside of the tubular member, lowering a flow string into the tubular member to convey uids received from the lower stratum to the' surface, and effecting a barrier between the flow string and the interior of the tubular member so that fluids from the two strata cannot commingle within the tubular member.

17. The method of producing wells which includes positioning a tubular member in a well so as to extend through two productive strata, said tubular member having perforations opposite said strata, effecting a barrier between the tubular member and the well walls so that fluids from the two strata cannot commingle on the outside of the tubular member, setting a second tubular member in the well so as to extend from within the bottom of the first tubular member into a third productive stratum, said second tubuiar member having perforations opposite said third stratum, 4eiiecting a barrier between the bottom of the first tubular member and the well walls and between the bottom of the first tubular member and the top of the second tubular member, lowering a first flow string into the first tubular member, effecting a barrier between the first oW string and the first tubular member so as to prevent commingling of uids from the first two strata within the first tubular member, and lowering a second ow string within the first flow string, and effecting a barrier between the second ow string and the second tubular member so that fluids from the third stratum may be conveyed thereby to the surface without commingling with uids received from the first two strata.

18. 'I'he method of producing wells which includes positioning a tubular means in a well so as to extend through three productive strata, said tubular means having perforations opposite each of said strata, effecting barriers between the tubular means and the well walls so that the fluids from the three strata cannot commingle on the outside of the tubular means, lowering a first flow string into said tubular means and effecting a. barrier between said first flow string and said tubular means to prevent commingling of fiuids from the first two strata within the tubular means, lowering a second flow string through said first flow string, and effecting a barrier between said second ow string and said tubular means so that the fiuids from the second and third strata cannot commingle within said tubular means, thereby permitting the uid from the first stratum to be conveyed to the surface through the space between the tubular means and the first ow string, the uid from the second productive stratum to be conveyed to the surface through the space between the rst and second ow strings, and the fluid from the third productive stratum to be conveyed to the surface through the second fiow string without commingling.

' 19. The method of producing wells which includes positioning a tubular means in a-well so as to extend through three productive strata, said tubular means having perforations opposite each of said strata, effecting a rst exterior barrier between the tubular means and the well walls so that the uids from the rst and second strata cannot commingle on the outside of the tubular means, effecting a second exterior barrier between the tubular means and the well walls so that the fluids from the second and third strata cannot commingle on the outside of the tubular means, lowering a first ow string into said tubular means and effecting a barrier between the first flow string and said tubular means to cooperate with the rst exterior barrier to prevent commingling of fluids from the -rst and second strata within the' tubular means, lowering a second ow string through the first flow string and effecting a barrier between the second flow string and said tubular means to cooperate with the second exterior barrier so that the uids from the second and third strata cannot commingle within the tubular means.

ARTHUR L. ARMENTROUT. ELWIN B. HALL. 

